Automatic conveyor systems often transport a plurality of goods in parcels which must be individually identified to be properly sorted. Parcels such as airline baggage, shipping containers, production inventory, machine parts, and component parts are often identified with flexible tags or labels. Electromagnetic sensing is sometimes used to identify the flexible tags or labels on individual parcels placed upon a conveyor. When the parcels are oriented so that the identification tags are located beneath the parcel on a conveyor, they cannot be read by conventional line of sight reading equipment located above the conveyor. Thus, what is needed is one or more apertures positioned upon the conveyor bed, so that electromagnetic or electrostatic sensing equipment located beneath the conveyor can read the identification tag located beneath the parcel through the conveyor belt.
U.S. Pat. No. 5,450,492 issuing to Hook et al. on Sep. 12, 1995 is representative of an electronic identification system having a transmitter for generating an electromagnetic excitation signal, and one or more transponder s with variable time and frequency.
U.S. Pat. No. 4,724,953 issuing to Winchester on Feb. 16, 1988 discloses a food conveyor apparatus having a plurality of rows of oblong holes positioned along the length of the conveyor, with each row offset from adjacent rows of holes. The platform supports an endless mesh conveyor belt. The plurality of holes and the endless mesh conveyor belt allow food debris to fall through the conveyor belt and platform to simplify cleaning in a food processing environment.
U.S. Pat. No. 5,040,549 issuing to Ray on Aug. 20, 1991 discloses a belt conveyor for feeding tobacco into a cutting machine. A plate supporting the conveyor belt has a plurality of apertures through which debris may fall or be swept, and a means below the plate to collect the particulate material.
To be effective, the identification tags on individual parcels must be oriented to position the identification tags in relation to the reader antenna positioned in proximity to the conveyor belt. Manual orientation of the parcels to orient the identification tags in relation to reader antenna is labor intensive and time consuming. Where the identification tag is positioned beneath the parcel, it cannot easily be read by reader antenna positioned above the conveyor. Thus, what is needed is a way to position the reader antenna beneath the conveyor belt to read identification tags located beneath the parcel.